package collection;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;

public class GenericDemo {
    public static void main(String[] args) {
            Collection<Point> c = new ArrayList<>();
            c.add(new Point(1,2));
            c.add(new Point(3,4));
            c.add(new Point(5,6));
            c.add(new Point(7,8));

            Iterator<Point> it = c.iterator();
            while (it.hasNext()){
                Point p = it.next();
                System.out.println(p);
            }

            for (Point str:c){
                System.out.println(str);
            }














        /*
        Collection<String> c = new ArrayList<>();
        c.add("one");
        c.add("two");
        c.add("three");
        c.add("four");
        c.add("five");
        //c.add(123);//编译错误,123是int类型,违背了集合c所只想的泛型的类型String

        //迭代器所指向的泛型应该与其遍历的集合的泛型一致
        Iterator<String> it = c.iterator();
        while (it.hasNext()){
            String str = it.next();
            System.out.println(str);
        }

        for (String str1:c){
            System.out.println(str1);
        }

         */

















    }
}
